. >>> to pakistan fresh steps the u.s. took to track down osama bin laden. the cia reportedly ran a phony vaccination project in abbottabad, part of a plan to gather dna to figure out if the bin laden family was there and the pakistani doctor suspected of running the operation is being detained. r re reza sayah what do you know. >> reporter: it's not clear but they need to confirm he was living and hiding out in abbottabad. the intelligence source tells us that this doctor staged a fake vaccination campaign and he was advertising free shots and free vaccinations for the kids in abbottabad. the british paper "the guardian" is reported he hired two nurses who went around house to house and the plan was to get to the bin laden kids, extract blood and use syringes to match their dna with bin laden's sister's dna who died in boston last year. we spoke with residents of abbottabad and six of them tell us they went to house to house offering free vaccinations. we hadn't verified if they went from compound to compound. >> unfortunately we're having some problems tod